Air conditioner and control method thereof

ABSTRACT

An air conditioner controls supply of refrigerant so that the refrigerant is first supplied to one or more indoor units in operation from an outdoor unit, and is then supplied to a hot water generator, thereby sufficiently supplying refrigerant to the indoor units in heating operation even when the hot water generator is operated.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No. 10-2010-0088105 filed on Sep. 8, 2010 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND

1. Field

Embodiments of the present disclosure relate to an air conditioner equipped with a plurality of indoor units to heat and cool indoor spaces using refrigerant supplied from an outdoor unit and a hot water generator to generate hot water using refrigerant supplied from the outdoor unit, and a control method of the air conditioner.

2. Description of the Related Art

In general, an air conditioner includes a refrigeration cycle, and is an apparatus configured to heat or cool an indoor space by implementation of the refrigeration cycle.

In recent years, various kinds of air conditioners have been developed. For example, there is an air conditioner to allow hot water generated by a hot water generator to be used to heat the indoor space or supply hot water. Such an air conditioner includes an indoor unit to directly exchange heat with indoor air so as to heat and cool the indoor space, and a hot water generator to heat water using high temperature refrigerant supplied to the hot water generator from a compressor of an outdoor unit.

SUMMARY

Therefore, it is an aspect of the present disclosure to provide an air conditioner equipped with a plurality of indoor units to heat and cool indoor spaces using refrigerant supplied from an outdoor unit and a hot water generator to generate hot water using refrigerant supplied from the outdoor unit, and a control method of the air conditioner.

Additional aspects of the disclosure will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the disclosure.

In accordance with one aspect of the present disclosure, a control method of an air conditioner, the air conditioner including an outdoor unit, one or more indoor units to heat an indoor space by refrigerant supplied from the outdoor unit, and a hot water generator to heat water by the refrigerant supplied from the outdoor unit, the control method includes controlling supply of the refrigerant so that the refrigerant is first supplied to one or more indoor units in operation from the outdoor unit, and is then supplied to the hot water generator.

The controlling supply of the refrigerant may be executed by controlling an opening degree of a hot water expansion valve provided at the hot water generator.

The control method of the air conditioner may further include identifying whether there is not any one indoor unit in operation among the indoor units, and if there is no indoor unit in operation, opening the hot water expansion valve of the hot water generator to the maximum opening degree thereof.

The control method of the air conditioner may further include identifying whether there is not any one indoor unit in operation among the indoor units, if there is any one indoor unit in operation, identifying whether a pressure at a discharge side of a compressor in the outdoor unit is less than a reference pressure, and if the pressure at the discharge side of the compressor is less than the reference pressure, opening the hot water expansion valve to the minimum opening degree thereof.

The control method of the air conditioner may further include identifying whether there is not any one indoor unit in operation among the indoor units, if there is any one indoor unit in operation, identifying a temperature of water which is discharged from the hot water generator, and if the temperature of the discharge water is less than a reference temperature, opening the hot water expansion valve to the minimum opening degree thereof.

The control method of the air conditioner may further include identifying whether there are one or more indoor units in operation among the indoor units, identifying the amount of refrigerant used being used in one or more indoor units in operation among the indoor units, summing all the amount of refrigerant used in one or more indoor units in operation to calculate the total amount of refrigerant used, and opening the hot water expansion valve to the opening degree thereof corresponding to the total amount of refrigerant used.

When the total amount of refrigerant used in one or more indoor units is relatively great, the hot water expansion valve may be opened to the relatively small opening degree thereof, and when the total amount of refrigerant used in one or more indoor units is relatively less, the hot water expansion valve may be opened to the relatively great opening degree thereof.

Each of the maximum total amount of refrigerant used in one or more indoor units and the maximum amount of refrigerant used in the hot water generator may be equal to the amount of refrigerant supplied from the outdoor unit, and the sum of the total amount of refrigerant used in one or more indoor units in operation among the indoor units and the amount of refrigerant used in the hot water generator in operation may be equal to or lesser than the amount of refrigerant supplied from the outdoor unit.

In accordance with another aspect of the present disclosure, an air conditioner includes an outdoor unit, one or more indoor units to heat an indoor space by refrigerant supplied from the outdoor unit, a hot water generator to heat water by refrigerant supplied from the outdoor unit, a hot water expansion valve arranged at the hot water generator to control the amount of refrigerant which is supplied to the hot water generator, the hot water expansion valve being formed as a flow regulating valve capable of controlling an opening degree thereof, and a control unit to allow the hot water expansion valve to be opened to an opening degree thereof corresponding to the total amount of refrigerant used being used in the one or more indoor units.

The control unit may identify whether there is not any one indoor unit in operation, and then open the hot water expansion valve to the maximum opening degree thereof when there is no indoor unit in operation.

The outdoor unit may include a compressor to compress refrigerant and a pressure sensing sensor to sense a pressure at a discharge side of the compressor, and the control unit may identify the pressure at the discharge side of the compressor, and then open the hot water expansion valve to the minimum opening degree thereof when the pressure at the discharge side of the compressor is equal to or lesser than a reference pressure.

The hot water generator may include a heating tank to heat water by refrigerant and a discharge water temperature sensing sensor to sense a temperature of water which is discharged from the heating tank, and the control unit may identify the temperature of the water which is discharged from the heating tank, and then open the hot water expansion valve to the minimum opening degree thereof when the temperature of the discharge water is equal to or lesser than a reference temperature.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects of the disclosure will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a view schematically illustrating a refrigeration cycle applied to an air conditioner according to an exemplary embodiment of the present disclosure;

FIG. 2 is a block diagram illustrating control of the air conditioner according to the exemplary embodiment of the present disclosure; and

FIG. 3 is a flowchart illustrating control of the air conditioner according to the exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

As shown in FIG. 1, an air conditioner according to an exemplary embodiment of the present disclosure includes an outdoor unit 10 arranged at an outdoor space to exchange heat with outdoor air, indoor units 20 to exchange heat with indoor air so as to heat and cool indoor spaces, respectively, a hot water generator 30 to heat water by refrigerant so as to generate hot water, and a hot water consuming device 40 to use the hot water generated by the hot water generator 30. In such an air conditioner, hot or cold air generated through implementation of the refrigeration cycle of the air conditioner may be used to heat and cool the indoor space, and hot water generated by the hot water generator 30 may be supplied to the hot water consuming device 40 such as a floor heater or a hot water supply device.

The outdoor unit 10 includes a compressor 11 to compress refrigerant, an outdoor heat exchanger 12 to allow the refrigerant to exchange heat with outdoor air, a four-way valve 13 to selectively supply the refrigerant compressed by the compressor 11 to any one of the outdoor heat exchanger 12 and each indoor unit 20, and a pressure sensing sensor 14 to sense pressure of the refrigerant discharged from the compressor 11, namely, pressure of the refrigerant which passes through a path provided at a discharge side of the compressor 11.

The indoor unit 20 is comprised of a plurality of indoor units 20 which may independently heat and cool a plurality of indoor spaces, respectively. Such an indoor unit 20 is a device to heat and cool the indoor space while allowing the refrigerant supplied from the outdoor unit 10 to exchange heat with indoor air. Each indoor unit 20 includes an indoor heat exchanger 21 to allow the refrigerant to exchange heat with indoor air, and an air conditioning expansion valve 22 to decompress and expand the refrigerant.

The hot water generator 30 is a device to heat water by the refrigerant supplied from the outdoor unit 10 so as to generate hot water. The hot water generator 30 includes a heating tank 31 to heat water while allowing the refrigerant supplied from the outdoor unit 10 to exchange heat with water supplied from the hot water consuming device 40, a hot water expansion valve 32 to decompress and expand the refrigerant passing through the heating tank 31, and a discharge water temperature sensing sensor 33 to sense temperature of the hot water which is supplied to the hot water consuming device 40 from the heating tank 31 after undergoing heat exchange with the refrigerant in the heating tank 31. Herein, the hot water expansion valve 32 may be a flow regulating valve capable of controlling an opening degree thereof to regulate the amount of refrigerant which is supplied to the hot water generator 30.

In this case, indoor heating by the indoor units 20 and hot water generation by the hot water generator 30 may be performed independently of each other. Consequently, either the maximum total amount of refrigerant used in the indoor units when all indoor units 20 are operated or the maximum amount of refrigerant used in the hot water generator 30 when the hot water generator 30 is operated at full load is practically equal to the amount of refrigerant supplied from the outdoor unit 10. Also, when the indoor heating by the indoor units 20 is performed simultaneously with the hot water generation by the hot water generator 30, the sum of the total amount of refrigerant used in indoor units 20 and the amount of refrigerant used in the hot water generator 30 is always maintained at or below the amount of refrigerant supplied from the outdoor unit 10, in order to prevent generation of a cold wind in the indoor units 20.

As shown in FIG. 2, the air conditioner also includes a control unit 50 to control overall operation of the air conditioner, a valve drive unit 60 to control the air conditioning expansion valve 22 and the hot water expansion valve 32, and a compressor drive unit 70 to control the compressor 11. In detail, the control unit 50 controls the air conditioning expansion valve 22, the hot water expansion valve 32, and the compressor 11 by the valve drive unit 60 and the compressor drive unit 70, based on pressure and temperature information transferred from the pressure sensing sensor 14 and discharge water temperature sensing sensor 33 described above.

Hereinafter, a control method of the air conditioner configured as described above will be described in detail with reference to FIG. 3.

The control method of the air conditioner according to the present exemplary embodiment sums the amount of refrigerant used being used in one or more indoor units 20 in operation among a plurality of indoor units 20 to derive the total amount of refrigerant used ΣQ, and then opens the hot water expansion valve 32 to the opening degree thereof corresponding to the total amount of refrigerant used ΣQ, thereby regulating the amount of refrigerant which is supplied to the hot water generator 30. That is, the hot water expansion valve 32 is controlled so that refrigerant is first supplied to one or more indoor units 20 in operation from the outdoor unit 10, and is then supplied to the hot water generator 30. This serves to uniformly maintain the amount of refrigerant which is supplied to the indoor units 20, regardless of whether or not the hot water generator 30 is operated. Therefore, in accordance with the above-mentioned configuration, it may be possible to prevent the refrigerant, which may be inadequately supplied to one or more of the indoor units 20 when the hot water generator 30 is operated during heating operation mode, from causing generation of a cold wind in the indoor units 20.

To this end, the control method of the air conditioner, if the hot water generator 30 is operated by a user (operation 100), first identifies whether there is not any one indoor unit 20 in operation among a plurality of indoor units 20 (operation 110). Thereafter, if there is no indoor unit 20 in operation among a plurality of indoor units 20, the hot water expansion valve 32 is opened to the maximum opening degree thereof (operation 120). In other words, if there is no indoor unit 20 in operation among a plurality of indoor units 20, all refrigerant supplied from the outdoor unit 10 is used to operate the hot water generator 30.

On the contrary, the control method of the air conditioner senses refrigerant pressure P at the discharge side of the compressor 11 by the pressure sensing sensor 14 (operation 130) if there is any one indoor unit 20 in operation among a plurality of indoor units 20, and then indentifies whether the sensed refrigerant pressure P is less than the reference pressure Pref (operation 140). If the refrigerant pressure P is less than the reference pressure Pref, the hot water expansion valve 32 is opened to the minimum opening degree thereof (operation 150).

In this case, the reference pressure Pref is the refrigerant pressure P at the discharge side of the compressor 11 during an operation mode of all the indoor units 20. Accordingly, when the hot water generator 30 is operated in a state in which the pressure at the discharge side of the compressor 11 is less than the reference pressure Pref, the refrigerant may be inadequately supplied to one or more of the indoor units 20. As a result, generation of a cold wind may be caused in the indoor units 20 in heating operation. Therefore, in such a case, the hot water generator 30 is opened to the minimum opening degree thereof so that the hot water generator 30 is practically not operated while preventing the refrigerant from remaining in the hot water generator 30.

Further, the control method of the air conditioner senses temperature T of water which is discharged from the heating tank 31 of the hot water generator 30 by the discharge water temperature sensing sensor 33 mounted at the hot water generator 30 (operation 160) if the pressure P at the discharge side of the compressor 11 is equal to or greater than the reference pressure Pref, and then indentifies whether the sensed discharge water temperature T is less than the reference temperature Tref (operation 170).

If the discharge water temperature T is less than the reference temperature Tref, the refrigerant to exchange heat with water while passing through the heating tank 31 may be rapidly cooled by the water, thereby rapidly dropping the refrigerant pressure P at the discharge side of the compressor 11. Accordingly, when the refrigerant pressure P at the discharge side of the compressor 11 is rapidly dropped, the refrigerant may be inadequately supplied to one or more of the indoor units 20. As a result, generation of a cold wind may be caused in the indoor units 20 in heating operation. Therefore, when the discharge water temperature T is less than the reference temperature Tref, the hot water generator 30 is opened to the minimum opening degree thereof so that the hot water generator 30 is practically not operated while preventing the refrigerant from remaining in the hot water generator 30.

Although the above-mentioned method senses the pressure P at the discharge side of the compressor 11 (operation 130), and then senses the discharge water temperature T (operation 160) if the pressure P at the discharge side of the compressor 11 is equal to or greater than the reference pressure Pref, the method may also be executed in reverse order. That is, the method may sense the discharge water temperature T (operation 160), and then identify the pressure P at the discharge side of the compressor 11 (operation 130) if the discharge water temperature T is equal to or greater than the reference temperature Tref.

Thereafter, the control method of the air conditioner, if the discharge water temperature T is equal to or greater than the reference temperature Tref, respectively identifies the amount of refrigerant used being used for heating in indoor units 20 in operation among a plurality of indoor units 20, and then sums the amount of refrigerant used in each indoor unit 20 in operation to identify the total amount of refrigerant used ΣQ (operation 180). Subsequently, the hot water expansion valve 32 is opened to the opening degree thereof corresponding to the calculated total amount of refrigerant used ΣQ (operation 190). That is, the opening degree of the hot water expansion valve 32 is controlled so that the remaining refrigerant, except for the total amount of refrigerant used ΣQ being used in the indoor units 20 in operation among refrigerant supplied from the outdoor unit 10, is supplied to the hot water generator 30.

In the present exemplary embodiment, a range of the total amount of refrigerant used ΣQ in one or more indoor units 20 in operation among a plurality of indoor units 20 is set in a multistage manner to control the opening degree of the hot water expansion valve 32 according to the set range of the total amount of refrigerant used. In other words, when the total amount of refrigerant used ΣQ is relatively great, the hot water expansion valve 32 is opened to the relatively small opening degree thereof to decrease the amount of refrigerant which is supplied to the hot water generator 30. On the other hand, when the total amount of refrigerant used ΣQ is relatively less, the hot water expansion valve 32 is opened to the relatively great opening degree thereof to increase the amount of refrigerant which is supplied to the hot water generator 30.

As described above, when the opening degree of the hot water expansion valve 32 is controlled according to the total amount of refrigerant used in one or more indoor units 20 in operation, the amount of refrigerant to be supplied to the indoor units 20 may be sufficient even when the hot water generator 30 is operated during heating operation by the indoor units 20. As a result, it may be possible to prevent a cold wind from being generated in the indoor units 20.

The present exemplary embodiment discloses an air conditioner including a plurality of indoor units 20, but is not limited thereto. Thus, an air conditioner including a single indoor unit 20 may also be applied.

As is apparent from the above description, the air conditioner according to an aspect of the present disclosure may control the opening degree of the hot water expansion valve so that the remaining refrigerant, except for the total amount of refrigerant used being used in the indoor units among refrigerant supplied from the outdoor unit, is supplied to the hot water generator, thereby sufficiently supplying refrigerant to the indoor units in operation even when the hot water generator is operated.

Although a few embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. 

What is claimed is:
 1. A control method of an air conditioner, wherein the air conditioner comprises an outdoor unit, one or more indoor units to heat an indoor space by refrigerant supplied from the outdoor unit, and a hot water generator to heat water by the refrigerant supplied from the outdoor unit, the control method comprising: controlling supply of the refrigerant so that the refrigerant is first supplied to one or more indoor units in operation from the outdoor unit, and is then supplied to the hot water generator.
 2. The control method of the air conditioner according to claim 1, wherein the controlling supply of the refrigerant is executed by controlling an opening degree of a hot water expansion valve provided at the hot water generator.
 3. The control method of the air conditioner according to claim 2, further comprising: identifying whether there is not any one indoor unit in operation among the indoor units; and if there is no indoor unit in operation, opening the hot water expansion valve of the hot water generator to the maximum opening degree thereof.
 4. The control method of the air conditioner according to claim 2, further comprising: identifying whether there is not any one indoor unit in operation among the indoor units; if there is any one indoor unit in operation, identifying whether a pressure at a discharge side of a compressor in the outdoor unit is less than a reference pressure; and if the pressure at the discharge side of the compressor is less than the reference pressure, opening the hot water expansion valve to the minimum opening degree thereof.
 5. The control method of the air conditioner according to claim 2, further comprising: identifying whether there is not any one indoor unit in operation among the indoor units; if there is any one indoor unit in operation, identifying a temperature of water which is discharged from the hot water generator; and if the temperature of the discharge water is less than a reference temperature, opening the hot water expansion valve to the minimum opening degree thereof.
 6. The control method of the air conditioner according to claim 2, further comprising: identifying whether there are one or more indoor units in operation among the indoor units; identifying the amount of refrigerant used being used in one or more indoor units in operation among the indoor units; summing all the amount of refrigerant used in one or more indoor units in operation to calculate the total amount of refrigerant used; and opening the hot water expansion valve to the opening degree thereof corresponding to the total amount of refrigerant used.
 7. The control method of the air conditioner according to claim 6, wherein: when the total amount of refrigerant used in one or more indoor units is relatively great, the hot water expansion valve is opened to the relatively small opening degree thereof; and when the total amount of refrigerant used in one or more indoor units is relatively less, the hot water expansion valve is opened to the relatively great opening degree thereof.
 8. The control method of the air conditioner according to claim 1, wherein: each of the maximum total amount of refrigerant used in one or more indoor units and the maximum amount of refrigerant used in the hot water generator is equal to the amount of refrigerant supplied from the outdoor unit; and the sum of the total amount of refrigerant used in one or more indoor units in operation among the indoor units and the amount of refrigerant used in the hot water generator in operation is equal to or lesser than the amount of refrigerant supplied from the outdoor unit.
 9. An air conditioner comprising: an outdoor unit; one or more indoor units to heat an indoor space by refrigerant supplied from the outdoor unit; a hot water generator to heat water by refrigerant supplied from the outdoor unit; a hot water expansion valve arranged at the hot water generator to control the amount of refrigerant which is supplied to the hot water generator, the hot water expansion valve being formed as a flow regulating valve capable of controlling an opening degree thereof; and a control unit to allow the hot water expansion valve to be opened to an opening degree thereof corresponding to the total amount of refrigerant used being used in the one or more indoor units.
 10. The air conditioner according to claim 9, wherein the control unit identifies whether there is not any one indoor unit in operation, and then opens the hot water expansion valve to the maximum opening degree thereof when there is no indoor unit in operation.
 11. The air conditioner according to claim 9, wherein: the outdoor unit comprises a compressor to compress refrigerant, and a pressure sensing sensor to sense a pressure at a discharge side of the compressor; and the control unit identifies the pressure at the discharge side of the compressor, and then opens the hot water expansion valve to the minimum opening degree thereof when the pressure at the discharge side of the compressor is equal to or lesser than a reference pressure.
 12. The air conditioner according to claim 9, wherein: the hot water generator comprises a heating tank to heat water by refrigerant, and a discharge water temperature sensing sensor to sense a temperature of water which is discharged from the heating tank; and the control unit identifies the temperature of the water which is discharged from the heating tank, and then opens the hot water expansion valve to the minimum opening degree thereof when the temperature of the discharge water is equal to or lesser than a reference temperature.
 13. An air conditioner comprising: an outdoor unit arranged at an outdoor space to exchange heat with outdoor air; one or more indoor units indoor units to exchange heat with indoor air so as to heat and cool indoor spaces by refrigerant supplied from the outdoor unit, each indoor unit including an indoor heat exchanger and an air conditioning expansion valve; and a hot water generator to heat water by refrigerant supplied from the outdoor unit, the hot water generator including a heating tank to heat water by refrigerant, a discharge water temperature sensing sensor to sense a temperature of water which is discharged from the heating tank and a hot water expansion valve, wherein the outdoor unit includes a compressor to compress refrigerant, an outdoor heat exchanger to allow the refrigerant to exchange heat with outdoor air, a valve to selectively supply the refrigerant compressed by the compressor to any one of the outdoor heat exchanger and each indoor unit, and a pressure sensing sensor to sense pressure of the refrigerant discharged from the compressor.
 14. The air conditioner according to claim 13, further comprising a control unit to control overall operation of the air conditioner, the control unit including a valve drive unit to control the air conditioning expansion valve and the hot water expansion valve, and a compressor drive unit to control the compressor, wherein the control unit controls the air conditioning expansion valve, the hot water expansion valve, and the compressor by the valve drive unit and the compressor drive unit, based on pressure and temperature information transferred from the pressure sensing sensor and discharge water temperature sensing sensor.
 15. The air conditioner according to claim 14, wherein the control units controls the hot water expansion valve to be opened to an opening degree thereof corresponding to the total amount of refrigerant used being used in the one or more indoor units.
 16. The air conditioner according to claim 14, wherein the control unit identifies whether there is not any one indoor unit in operation, and then opens the hot water expansion valve to the maximum opening degree thereof when there is no indoor unit in operation.
 17. The air conditioner according to claim 14, wherein the control unit identifies the pressure at the discharge side of the compressor, and then opens the hot water expansion valve to the minimum opening degree thereof when the pressure at the discharge side of the compressor is equal to or lesser than a reference pressure.
 18. The air conditioner according to claim 14, wherein the control unit identifies the temperature of the water which is discharged from the heating tank, and then opens the hot water expansion valve to the minimum opening degree thereof when the temperature of the discharge water is equal to or lesser than a reference temperature. 